During an interventional procedure performed in a fluoroscopy suite, multiple sets of fluoroscopic images during contrast injection are acquired. A fluoroscopic unit has an x-ray tube, which emits x-rays and x-ray detector. Contrast material is injected into a blood vessel. Each set of fluoroscopic images obtained during an injection of contrast into a blood vessel is referred to as “run”. Each run is performed with the patient as still as possible to prevent motion artifact. The initial image is prior to the injection of contrast material serves as a template for subtraction. Subsequent images after the injection of contrast material are obtained and a digital subtraction angiogram (DSA) is obtained. Each view (e.g. orthogonal Anterior-Posterior (AP) and Lateral) will have multiple images and the total number of images is based on the frame rate and the time of acquisition. For example, a frame rate of 15 images/second for a time of 6 seconds will have 90 images for each view or a total of 180 images. These DSA images are interpreted by the physician. The physician analyzes these images and can then make adjustments to the catheter(s), wire(s) or the positions of the fluoroscopy unit(s). Multiple sets of images are typically obtained throughout the procedure.
Orthogonal acquisition of data provides information in the superior-inferior direction (head-toe), the transverse (left-right or medial-lateral) direction and the anterior-posterior (front-back) direction. The images are displayed on two separate monitors. The physician can analyze each monitor and can use this information to track the course of a blood vessel or catheter as it moves through the patient.